It'd be interesting looking at histograms rather than averages and separating out cash from credit card tips. Most taxi rides, I'm paying cash because I don't

It'd be interesting looking at histograms rather than averages and separating out cash from credit card tips. Most taxi rides, I'm paying cash because I don't want to be bitched out by the taxi driver about using a credit card. With cash, I'm more concerned about minimizing the amount of change so I'll usually do something like hand them a 20 and say "can I get 3/4/5 dollars back". That could partially explain some of the weird shapes in the data.